In our society, we must communicate with other people. A great deal of communication is performed on a person-to-person basis by the simple means of speech. If we travel in buses or stand in football match queues, we are likely to have conversations in which we give information or opinions, and sometimes have our views challenged by other members of society. Face-to-face contact is by no means the only form. of communication and during the last two hundred years the art of mass communication has become one of the dominating factors of contemporary society. Two things above others have caused the enormous growth of the communication industry. Firstly, inventiveness has led to advances in printing, photography, and so on. Secondly, speed has revolutionized the transmission and reception of communications so that local news often takes a back seat to national news. No longer is the possession of information confined to a privileged minority. Forty years ago people used to flock to the cinema, but now far more people sit at home and turn on the TV to watch a program that is being channeled into millions of homes. Communication is no longer merely concerned with the transmission of information. The modern communications industry influences the way people live in society and broadens their horizons by allowing access to information, education and entertainment. The printing, broadcasting and advertising industries are all involved with their informing, educating and entertaining functions. Although a great deal of the material communicated by the mass media is very valuable to the individual and to the society of which he is a part, the vast modern network of communications is open to abuse. However, the mass media are with us for better, for worse, and there is no turning back.
The author probably means that speech on a person-to-person basis is the______means of communication.

A. primary
B. secondary
C. auxiliary
D. optional